Evaluation of the Anti-amyloidogenic and Fibril-Destabilizing Effects of Salvia officinalis Flower Extract Against Hen’s Egg White Lysozyme: An In Vitro Study

Abstract Amyloid plaques or fibrils are deposits of abnormal proteins that mostly contain β-sheets, which accumulate in different organs and tissues, resulting in impaired tissue function and causing fatal and debilitating diseases. In this study, the effects of Salvia officinalis extract (SOE), pre...
Ausführliche Beschreibung

Abstract Amyloid plaques or fibrils are deposits of abnormal proteins that mostly contain β-sheets, which accumulate in different organs and tissues, resulting in impaired tissue function and causing fatal and debilitating diseases. In this study, the effects of Salvia officinalis extract (SOE), prepared from its flowers, on both prevention of amyloid plaques formation and removal of accumulated fibrils were investigated. Therefore, 14 mg/ml of hen egg-white lysozyme (HEWL) was incubated in the absence and presence of 7, 14 and 28 mg/ml of SOE in high temperature and acidic pH to form amyloid fibrils. In this line, thioflavin T (THT), 1-anilinonaphthalene-8-sulfonic acid (ANS) fluorescence test, Congo red absorbance test, Circular dichroism, and field-emission scanning electron microscopy were employed to study the effect of the extract on these processes. The results indicate that SOE presents a strong anti-amyloidogenic activity. The extract to protein ratio of 0.5:1 (7:14 mg/ml) did not cause the formation of amyloid fibrils in the HEWL solution. However, it resulted in defibrillation of HEWL in a dose-dependent manner. Based on our result, the extract to protein ratio of 1:1 (14:14 mg/ml) was the best ratio to change the structure of long and massive HEWL fibrils to thin and little fibrils. In general, it can be concluded that SOE contains compounds that can be useful for the treatment of amyloid-dependent diseases. Ausführliche Beschreibung